My girlfriend’s son has destroyed my self-confidence

DEAR DEIDRE: Since I moved in with my girlfriend, my self-confidence has been ruined by her son.

Every day he makes digs about my appearance, and as hard as I try to ignore it, it’s really starting to get me down.

I’m 42, my girlfriend is 39 and she has a 17-year-old son from a previous marriage.

When she first asked if I’d be open to living with her I was over the moon, but since the day arrived, he’s had it in for me.

I’m no Adonis but I do eat healthily and I’m active.

He is pretty impressive physically. He’s an avid gym goer and constantly obsesses about how much he’s lifting or the latest supplement he’s taking.

At first, he started telling me how good the gym would be for me and said he could help me “shift the pounds”.

Now he constantly insults me, calling me “fatty” and “chubster”, and always comments on what I eat. The more I complain, the more he does it.

He’s making my life miserable and I’m at my wits’ end.

DEIDRE SAYS: Your girlfriend’s son sounds immature and insecure.

As he is growing into a man, he is putting you down to try and prove that he doesn’t need a new man around the house.

If he hasn’t enjoyed a good relationship with his own dad, the development of you moving in will be particularly difficult.

Talk to your girlfriend about what is happening and agree on an approach together.

Perhaps you can both talk to him about boundaries so he sees you are united and also that you don’t want to assume the position of his father figure.

The next time he criticises your physique, calmly explain you are happy the way you are and that you don’t need a live-in personal trainer.

Being calmly assertive with him will help. My support pack Raising Self-esteem will help, too.